With development of network technologies, a fourth generation (4G) mobile communication technology has been widely applied. 4G may include multiple network standards, for example, Long Term Evolution (LTE)-Time Division Duplex (TDD) and LTE-Frequency Division Duplex (FDD).
A 4G network provides only a packet switched domain (PS domain) service, and cannot provide a circuit switched domain (CS domain) service. However, second generation (2G) and third generation (3G) networks support both the PS domain service and the CS domain service. Currently, a voice service and a short message service are mainly provided by a CS domain, and a data service is mainly provided by a PS domain. To support both the PS domain service and the CS domain service, a dual-standby technology is currently used when the 4G network is deployed. A wireless terminal that uses the dual-standby technology has two radio frequency modules, where one radio frequency module is a master radio frequency module mainly configured to provide a PS domain service, and the master radio frequency module provides support for a 4G network; and the other radio frequency module is a slave radio frequency module, and the slave radio frequency module is mainly configured to provide a CS domain service.
In a process in which the wireless terminal that uses the dual-standby technology performs a PS domain service, when there is a 4G signal, the wireless terminal works in a 4G network, and when the 4G signal is weak, the wireless terminal is changed to a 2G or 3G network. When the 4G signal recovers to normal, the wireless terminal is changed to the 4G network again. Currently, an inappropriate configuration of the 4G network causes frequent changes of the wireless terminal between 4G and 2G/3G, and results in heavy network load and poor user experience.